1 files changed, 155 insertions, 0 deletions
diff --git a/lib/os2-spawn.c b/lib/os2-spawn.c
new file mode 100644
index 0000000..ac425a3
--- /dev/null
+++ b/lib/os2-spawn.c
@@ -0,0 +1,155 @@
+/* Auxiliary functions for the creation of subprocesses.  OS/2 kLIBC API.
+   Copyright (C) 2001, 2003-2020 Free Software Foundation, Inc.
+   Written by Bruno Haible <bruno@clisp.org>, 2003.
+
+   This program is free software: you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 3 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program.  If not, see <https://www.gnu.org/licenses/>.  */
+
+#include <config.h>
+
+/* Specification.  */
+#include "os2-spawn.h"
+
+/* Get _open_osfhandle().  */
+#include <io.h>
+
+#include <stdbool.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <errno.h>
+
+#include "cloexec.h"
+#include "error.h"
+#include "gettext.h"
+
+#define _(str) gettext (str)
+
+
+/* Duplicates a file handle, making the copy uninheritable.
+   Returns -1 for a file handle that is equivalent to closed.  */
+static int
+dup_noinherit (int fd)
+{
+  fd = dup_cloexec (fd);
+  if (fd < 0 && errno == EMFILE)
+    error (EXIT_FAILURE, errno, _("_open_osfhandle failed"));
+
+  return fd;
+}
+
+/* Returns a file descriptor equivalent to FD, except that the resulting file
+   descriptor is none of STDIN_FILENO, STDOUT_FILENO, STDERR_FILENO.
+   FD must be open and non-inheritable.  The result will be non-inheritable as
+   well.
+   If FD < 0, FD itself is returned.  */
+static int
+fd_safer_noinherit (int fd)
+{
+  if (STDIN_FILENO <= fd && fd <= STDERR_FILENO)
+    {
+      /* The recursion depth is at most 3.  */
+      int nfd = fd_safer_noinherit (dup_noinherit (fd));
+      int saved_errno = errno;
+      close (fd);
+      errno = saved_errno;
+      return nfd;
+    }
+  return fd;
+}
+
+int
+dup_safer_noinherit (int fd)
+{
+  return fd_safer_noinherit (dup_noinherit (fd));
+}
+
+void
+undup_safer_noinherit (int tempfd, int origfd)
+{
+  if (tempfd >= 0)
+    {
+      if (dup2 (tempfd, origfd) < 0)
+        error (EXIT_FAILURE, errno, _("cannot restore fd %d: dup2 failed"),
+               origfd);
+      close (tempfd);
+    }
+  else
+    {
+      /* origfd was closed or open to no handle at all.  Set it to a closed
+         state.  This is (nearly) equivalent to the original state.  */
+      close (origfd);
+    }
+}
+
+const char **
+prepare_spawn (const char * const *argv, char **mem_to_free)
+{
+  size_t argc;
+  const char **new_argv;
+  size_t i;
+
+  /* Count number of arguments.  */
+  for (argc = 0; argv[argc] != NULL; argc++)
+    ;
+
+  /* Allocate new argument vector.  */
+  new_argv = (const char **) malloc ((1 + argc + 1) * sizeof (const char *));
+  if (new_argv == NULL)
+    return NULL;
+
+  /* Add an element upfront that can be used when argv[0] turns out to be a
+     script, not a program.
+     On Unix, this would be "/bin/sh".  */
+  new_argv[0] = "sh.exe";
+
+  /* Put quoted arguments into the new argument vector.  */
+  size_t needed_size = 0;
+  for (i = 0; i < argc; i++)
+    {
+      const char *string = argv[i];
+      const char *quoted_string = (string[0] == '\0' ? "\"\"" : string);
+      size_t length = strlen (quoted_string);
+      needed_size += length + 1;
+    }
+
+  char *mem;
+  if (needed_size == 0)
+    mem = NULL;
+  else
+    {
+      mem = (char *) malloc (needed_size);
+      if (mem == NULL)
+        {
+          /* Memory allocation failure.  */
+          free (new_argv);
+          errno = ENOMEM;
+          return NULL;
+        }
+    }
+  *mem_to_free = mem;
+
+  for (i = 0; i < argc; i++)
+    {
+      const char *string = argv[i];
+
+      new_argv[1 + i] = mem;
+      const char *quoted_string = (string[0] == '\0' ? "\"\"" : string);
+      size_t length = strlen (quoted_string);
+      memcpy (mem, quoted_string, length + 1);
+      mem += length + 1;
+    }
+  new_argv[1 + argc] = NULL;
+
+  return new_argv;
+}